It might be your label is blocking the mouse and the button pressed() event never gets called since the mouse click is blocked. Try setting the mouse filter to either ignore or stop on the label and that might allow the button to be pressed even though the label is on top.
(If you are using Godot 2)
If you want to know when a label has been clicked, I would recommend using the 'mouse_enter()' and 'mouse_exit()' signals from control, set a boolean to true/false when the mouse has entered/exited and look for when the left/right/middle mouse button was just pressed. Then it's just a matter of checking if the boolean is true or false and doing the appropriate response.
You could do it with input_event, it would probably look something like this:
(I have not tested the code below, and wrote most of it from memory and looking at the documentation)
func _ready():
get_node(label_path_here).connect("input_event", self, "label_pressed");
func label_pressed(input_event):
if (input_event.type == input_event.MOUSE_BUTTON):
var label_size = get_node(label_path_here).get_size();
var label_pos = get_node(label_path_here).get_global_pos();
var mouse_pos = get_global_mouse_pos();
if (label_pos <= mouse_pos <= label_pos + label_size):
# Label clicked!
(If you are using Godot 3)
I think there is a similar signal control provides for telling whether the mouse is over it. Not sure though... Using input_event would be similar, if you make the changes needed for Godot 3's new InputEvent.
